Chromatography Forum

Mathew,

I reread the whole string of posts regarding your interest in a triple quad. It occurred to me that most of the posts are very informative but also very opinionated, (mine included).

I think these forums are a good way to get started. I would use them for advice and opinions to buy a stereo or plasma TV but maybe not a $150,000 mass spectrometer. I think if I buy a Sony and you buy a Sony it will operate identically in your house as well as mine. Not so with the MS. Blanket statements about level of detection can be misleading. All the MS vendors have different ion sources that do not behave identically from sample to sample. Also, a sample in mobile phase versus a plant extract will behave differently. You should check references, local support, user base, etc. for all the vendors. You should have the vendors run your samples. Thermo would be glad to.

Good Luck

Hi MS,

you'll be glad to know that we contacted our Thermo rep. He has provided us with a competitive quote for the TSQ Quantum Access... hopefully we can chat with a few users and see how our material pops out.

Are there any users here? I seem to recall someone expressing dissatisfaction with Thermo's triple quads, while praising their GC/MSs.

I have been using TSQ Quantum Discovery LCMSMS system for almost 5 years without any major problems. It works well and seems quite robust, especially when handling dirty samples.

good to hear chhubert. realizing that ionisation is compound specific, can I ask what sorts of sensitivity you are getting? e.g., what sorts of lloq do you normally bottom out at? are you working with animal or plant material? my samples will indeed be dirty (although I can do a few things about that).

Sensitivity wise, I don't really think you can beat the ABI 5000. But Analyst software is really bad for multi analyte analysis and the 5000 is pretty pricey.

In the lab. that I work at, we have 2 ABI QTrap 3200s, 1 ABI 3200, 4 Waters UPLC/TQDs, 1 Waters Quattro Premier XE, 2 Waters UPLC/LCT Premier XEs, 1 Waters HPLC/Quattro Micro, and 1 Waters HPLC/ZQ.

I prefer the Waters instruments (ease of use, software, low ng/mL sensitivity with protein precipitation methods).

Here's a link to the Karlovsky lab at the University of Goettingen: http://wwwuser.gwdg.de/~instphyt/karlovsky/index.html

They are using both Triple Quad and Ion Trap LC-MS.

I can put you in touch with the local Varian LC-MS rep if you like.

Hi Matthew,

Currently in my lab I am using a Agilent 6410. The Mass Hunter software is powerful and easy to use. I have not had a chance to use an ABI system, but I have friends who are using the Analyst software and they too complain about software hanging on them. Moreover, I think the ABI QTrap is not a true triple quad. The reason I say that is that, as a hybrid Ion trap-Triple quad system, it is definitely not as sensitve as a pure triple quad. For quantitation purposes, the ABI3200's dynamic range is also not as good as a triple quad due to the inherent mechanism of ion transmission.

As for sensitivity, I was able to achieve 2ppb detection and quantitation comfortably. I was told by my sales rep that Agilent will be coming out with an upgrade to further enhance the sensitivity of the 6410. I was told that this should make it comparable to an API4000.

I agree that information from Tandem MS is much more convienient and helpful than using NMR data.

FOr the case of unknowns, it really depends on whether you would expect those metabolites to be present at low levels. If yes, then go for sensitivity rather than flexibility.

Hi all,
Thanks for the feedback. I'm going back to work after a week's vacation, and I believe that we'll get the 6410 (if I can find 5 feet of bench space for it, wow).

chayyl, you mention:
I was told by my sales rep that Agilent will be coming out with an upgrade to further enhance the sensitivity of the 6410. I was told that this should make it comparable to an API4000.

What is the current mass range of your instrument? I saw old documentation that mentioned 1600 as the upper end, but it appears that the 6410 now ships at: 15-2000. Is this the update to which you refer?

Thanks again for all of the feedback, guys. Although the administrators haven't completely moved on this, yet, the icing will have been agilent's ridiculous pricing.